Niagara River Remedial Action Plan Stage 2 Update Report

They carried out the

They carried out the following actions to reduce bacterial inputs to the reservoir: }} Septic systems were repaired as necessary }} Water conservation was encouraged amongst area residents and farms }} Cattle access to watercourses were eliminated by fencing }} Improved manure storage facilities were encouraged and implemented at high priority locations }} Improved milkhouse washwater treatment was implemented at local dairy farms }} An overhead gull screen was constructed across the beach }} Groomed grass areas were created away from beach areas for use by Canada Geese }} No-till areas were encouraged adjacent to watercourses on farmers fields }} Buffer zones were created along watercourses and shorelines The magnitude of E. coli exceedances is also an important indicator of health risk at individual beaches. Figure 6a-d plots geometric mean E. coli concentrations by year for each of the public beaches in the AOC. Results show that the majority of exceedances of the PWQO still fall below Health Canada’s Canadian Recreational Water Quality Guideline of 200 E. coli CFU/100 ml, but at Binbrook Conservation beach a larger percentage of the results exceed this guideline as well, falling mostly within the 200-600 E. coli CFU/100 ml range. 2.5 Estimates and Sources of E. coli Loading from Different Sectors in the AOC The following are taken from the Niagara Water Quality Protection Strategy technical reports (Niagara Region, 2003). A simple mass balance model was used to estimate loadings of different point and nonpoint source pollutants from different types of land-use (urban, agricultural, and open space/parks/forest), including E. coli counts, on an annual basis. The counts per year were divided by the total area of land-use to standardize the data for comparison purposes. Results are shown in table 2. Table 2: Annual E. coli loads estimated from mass balance modelling by land-use type and/or source for the NiagaraRiver (Ontario) AOC. Loads for STPs within the AOC were not available, so the relative contributions of other land-uses to the total E. coli load are overestimated. Area refers to the cumulative area occupied by a given land-use type within the AOC, and Total Area refers to the sum of areas of all land-use types. SW=stormwater, CSO=combined sewer overflows, STP=sewage treatment plant. Land-Use Area (sq. km) % of Total Area E. coli (counts/sq. km/yr) E. coli (counts/yr) % of Total Urban SW 1.83E+15 20.4 Urban CSO 9.44E+14 10.6 Urban STP Unknown Unknown Urban (Total w/out STP) 20.50 1.71 1.35E+14 2.77E+15 31.0 Agriculture 760.37 63.47 7.76E+12 5.90E+15 65.9 Other 417.03 34.81 6.62E+14 2.76E+14 3.1 Source: after data from Regional Municipality of Niagara (2003). 168

Niagara river remedial action plan stage 2 update a) Binbrook Conservation b) Chippawa Conservation c) Queens Royal d) Ball Street Figure 6a-d: Magnitude of geometric mean E. coli exceedances for public beaches in the NiagaraRiver (Ontario) AOC for the period 1998-2005 (Binbrook Reservoir) and 2003-2005 (all other public beaches) Even without STP inputs accounted for, urban areas are shown to contribute substantially more E. coli per unit area than agricultural and rural areas in the AOC (almost two orders of magnitude more than agricultural areas and almost three orders more than open space/parks/forest). Based on the modelling exercise, of the total urban load, 66% is estimated to be from stormwater and 34% from combined sewer overflows (CSOs). However, agricultural and rural sources are still predicted to contribute 66% of the total load in surface water in the AOC. This is influenced in large part by the extent of this land-use (64% of total area). It is unknown to what extent these sources impact on individual beaches. Within the Welland watershed, Binbrook Conservation beach is exposed to sources within the reservoir catchment, but not downstream. Most of these sources are agricultural/rural in nature. Chippawa Creek Conservation Area is not directly connected to the Welland River and therefore would not be exposed to upstream or downstream (since the Welland flows both ways) sources. Although the Welland River confluence is upstream of the Queens Royal and Ball Street beaches on the NiagaraRiver and would contribute to the bacterial load somewhat, it contributes only a very small proportion of the total flow of the river. What can be assumed from the mass-balance modelling exercise above is that agricultural/rural sources are impacting the Binbrook 169